Sherlock Utters the Elusive L-Word in Latest Season 4 Trailer

See if you can crack this case: Who is Sherlock Holmes declaring his love for?

PBS and Masterpiece dropped a new trailer for Sherlock Season 4 (debuting Sunday, Jan. 1), and the promo includes a number of ominous images and voiceovers. However, the most dramatic moment comes at the very end of the 40-second video when Benedict Cumberbatch’s legendarily detached alter ego stares dead into the camera and announces, “I love you.”

As previously reported, the three new episodes — featuring Moriarty’s return and Wayward Pines‘ Toby Jones as infamous Holmes villain Culverton Smith — may end up being the show’s last. As leading man Benedict Cumberbatch told the UK edition of GQ magazine, “it feels like the end of an era, to be honest.”

Even if Sherlock were to go on, its fourth season “goes to a place where it will be pretty hard to follow on immediately,” the actor added.

Press PLAY above and then hit the comments with your theories about the tantalizing L-word mystery!